Chromium (Cr) has been known as an essential trace element in animal and human nutrition. Cr deficiency may result in various symptoms including increased concentrations of circulating insulin, elevated blood glucose and cholesterol, decreased insulin receptor number, elevated triglyceride and free fatty acid levels and reduced high-density lipoprotein (HDL) cholesterol levels. These metabolic abnormalities, in general, are associated with risk for and/or incidence of diabetes. Moreover, chromium levels in most organs decline with age and in diabetics the chromium levels are even lower-than in other healthy adults. Anderson, R. A., Clin. Physiol. Biochem. 4: 31-41 (1986).
Malnutrition associated with Cr deficiency brings an impaired glucose tolerance. However, inorganic Cr compounds are poorly absorbed by the gut, whereas organic Cr components are well absorbed in the body. Glucose Tolerance Factor (GTF) is an organic complex of chromium present in several natural sources, the richest among them is Brewer's yeast. GTF was found to improve glucose tolerance in 50% of elderly patients with impaired glucose tolerance after two months of treatment. Despite these effects, the structure of GTF has not been identified as of yet. Several naturally occurring organic Cr compounds have been proposed to serve as GTF, for example, a partially purified cationic Cr compound extracted from yeast, soluble in water and has an absorption spectrum at 260nm, or the low-molecular-weight Cr-binding substance isolated from mouse or rabbit liver or bovine colostrum which has anionic properties. These organic Cr compounds have heretofore been used as crude extracts and the properties of their individual components remain uncharacterized. Evans, G. W. et al., Biochem. Biophys. Res. Commun. 50:718-722 (1973).
Hwang et al (U.S. Pat. No. 4,985,439) attempted to purify the Glucose Tolerance Factor from autolyzed brewer'yeast, and claimed that the active fraction is a quinoline derivative. King, S. (U.S. Pat. No. 5,108,610) also tried to isolate and purify a material possessing Glucose Tolerance Factor activity from eukaryotic cell mass, and claimed that the active material is dithiochrome. In addition, some patents describe a number of synthetic Cr compounds, (Furman C. S. et al, U.S. Pat. No. 5,266,560; Jensen N. L., U.S. Pat. No. 5,194,615; Wong Y., U.S. Pat. No. 5,536,863 Evans G. W., U.S. Pat. No. 5,087,624 and U.S. Pat. No. 4,315,927; Hwang D. et al, U.S. Pat. No. 4,985,439). Some patents describe chromium picolinate as a hypoglycemic chromium compound (U.S. Pat. No. 5,087,623; U.S. Pat. No. 5,087,624; and U.S. Pat. No. 5,175,156). The present invention is directed to development of improved processes to isolate natural compositions, with or without active and stable organic Cr compounds, as well as having hypoglycemic and/or hypolipidemic activity, from natural sources including, but not limited to, Brewer's yeast and Saltbush plant.
The present invention relates to compositions having hypoglycemic and/or hypolipidemic activity with or without natural or synthetic chromium compounds for application to individuals at risk for or suffering from diabetes, CVD, and cell proliferative diseases by regulation of metabolic abnormalities and/or inhibition of metabolic abnormalities within the target cells. In the practice of the invention, the natural or synthetic chromium compounds can be applied to supplement traditional pharmaceutical, hormonal and/or nutritional therapies for diabetes.
Diabetes mellitus is a disease of metabolic disregulation, notably of glucose metabolism, and long-term vascular and neurologic complications. Diabetes has several clinical forms, the two major forms being insulin-dependent diabetes mellitus I (IDDM) and the non-insulin-dependent diabetes mellitus II (NIDDM). IDDM is rare, affecting one in 250 persons in the United States, where approximately 10,000 to 15,000 new cases are reported each year. Data suggest that the incidence of IDDM is increasing in Europe, where the highest prevalence is found in northern Europe, for example, more than one in every 150 Finns develop IDDM by 15 years of age. LaPorte, R. et al., in Diabetes in America, 2.sup.nd ed. Ed M. Harris, National institutes of Health, Bethesda, Md. NIH Publication No 95-1498, 1995.
NIDDM is common, with an overall prevalence of 6.6 percent in the United States. NIDDM has become one of the most frequent chronic diseases in most industrialized nations and the projected prevalence for the next decade is 10 percent. 600, 000 new cases are reported each year and one half of the NIDDM population are unaware of their disorder. The increase in the prevalence of NIDDM in the United States is commonly attributed to an aging population that is also increasingly obese and sedentary. The prevalence of NIDDM among persons older than 65 years exceeds 18 percent, and compared with normal-weight individuals, obese people with a body mass index greater than 30, are at 10 to 20 times greater risk for NIDDM. Although genetic and immunologic markers for IDDM have been identified, they are not enough nor sensitive enough to be used to define IDDM or distinguish IDDM and NIDDM. Harris, M. I., et al., Diabetes 36: 523 (1987); Bennett, P. H., et al., in International Textbook of Diabetes, ed Alberti KGMM, et al., John Wiley & Sons Ltd UK 1992, p148.